Cost–benefit analysis of far-UVC lamps for reducing indoor infection transmission in Switzerland and Germany: Insights from the CERN Airborne Model for Indoor Risk Assessment (CAiMIRA)

Far-UVC light (wavelengths 207–230 nm) can be used directly overhead and has germicidal capabilities to improve indoor air quality. This study evaluates the cost–benefit analysis of implementing far-UVC devices in various settings in Switzerland and Germany. To our knowledge, this is the first study to model the feasibility of direct-acting UVC light in occupied settings, diverging from the consensus on the use of upper-room germicidal UVA and UVB systems. We used the CERN Airborne Model for Indoor Risk Assessment (CAiMIRA) to model infection risk reduction in restaurants, offices, and waiting rooms, considering factors such as room size, occupancy, and ventilation rates. Three scenarios were analysed: a normal winter (22 weeks), a COVID-19-like pandemic (4-week wave), and a severe pandemic (8-week wave). Avoided infections were translated into healthcare, economic, and quality-adjusted life years (QALY) metrics. Costs included purchasing, installing, maintaining, and operating UVC lamps. In Switzerland, cost–benefit ratios ranged 30–290 during a normal winter, 65–430 during a COVID-like pandemic, and 2,300–20,500 during a severe pandemic. In Germany, cost–benefit ratios ranged 10–110 during a normal winter, 30–190 during a COVID-like pandemic, and 1,000–9,000 during a severe pandemic. Far-UVC lamps are a highly cost-effective solution for societies during normal winter and pandemic scenarios. Future studies should focus on implementation in the settings studied; they seem to represent a safe and effective measure for infectious disease control, but need real-world validation.